Abstract
In response to shading, plant leaves acclimate through a range of morphological, physiological and biochemical changes. Plants produce a myriad of structurally and functionally diverse metabolites that play many important roles in plant response to continually changing environmental conditions as well as abiotic and biotic stresses. To develop a clearer understanding of the effects of shade on soybeans at different growth stages, a comprehensive, three-year, stage-wise study was conducted. Leaf area, leaf thickness, stem diameter, chlorophyll contents, photosynthetic characteristics and other morphological and physiological features were measured along with biochemical assays for antioxidants such as superoxide dismutase, peroxidase and caralase and yield attributes of different soybean genotypes (Guixia 2, Nandou12, Nandong Kang-22, E61 and C103) under shading nets with 50% light transmittance. It was observed that early shading (VER1 and VER2) significantly decreased main stem length and main stem length/stem diameter. Later shading (R1R8 and R2R8) had significant effects on morphological characters such as branch number and pod height. In Nandou 12, the protein contents in plants shaded at R1R8, R2R8 and R5R8 were 9.20, 8.98 and 6.23% higher than in plants grown under normal light levels (CK), respectively, and the crude fat content was 9.31, 10.74 and 4.28% lower. The influence of shading in the later period on anatomy was greater than that in the earlier period. Shading reduced the light saturation point (LSP), the light compensation point (LCP) and the maximum photosynthetic rate (Pnmax), and increased the apparent quantum yield (AQ). Shading also increased the antioxidant enzyme activity in the plants, and this increase was greater with early shading than late. The variability in the chlorophyll (a + b) content and the chlorophyll a/b ratio in R2 stage plants was less than in R5 stage (VER5) plants. Similarly, the activity of antioxidant enzymes in R2 after returning the plants to normal light levels (VER2) was lower than in R5 after relighting (VER5). Compared with later shading, the early shading had a greater effect on the photosynthetic and related characteristics. The longer the shading time, the greater the adverse effects and the less able the plants' were to recover. The data collected in this study contribute to an understanding of the physiological mechanisms underlying the early and late growth stage acclimation strategies in different soybean genotypes subjected to shade stress.
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Claims 10
Claim · model-written summary
Early shading decreased main stem length and main stem length/stem diameter.
- Taxon
- soybean
Glycine maxt0 - Treatment
- early shading (VER1 and VER2)e1
- Outcome
- main stem length and main stem length/stem diametere1
- Direction
- decreasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e1“It was observed that early shading (VER1 and VER2) significantly decreased main stem length and main stem length/stem diameter”
Claim · model-written summary
Later shading had significant effects on branch number and pod height.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Later shading (R1R8 and R2R8)e2
- Outcome
- branch number and pod heighte2
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e2“Later shading (R1R8 and R2R8) had significant effects on morphological characters such as branch number and pod height”
Claim · model-written summary
In Nandou 12, protein content was higher under R1R8, R2R8 and R5R8 shading than under normal light.
- Taxon
- soybeanGlycine maxt0
- Material
- Nandou 12e3
- Treatment
- plants shaded at R1R8, R2R8 and R5R8e3
- Outcome
- protein contentse3
- Direction
- highere3
- Value
- 9.20, 8.98 and 6.23%e3
- Comparator
- normal light levels (CK)e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e3“In Nandou 12, the protein contents in plants shaded at R1R8, R2R8 and R5R8 were 9.20, 8.98 and 6.23% higher than in plants grown under normal light levels (CK), respectively”
Claim · model-written summary
In Nandou 12, crude fat content was lower under R1R8, R2R8 and R5R8 shading than under normal light.
- Taxon
- soybeanGlycine maxt0
- Material
- Nandou 12e3
- Treatment
- plants shaded at R1R8, R2R8 and R5R8e3
- Outcome
- crude fat contente4
- Direction
- lowere4
- Value
- 9.31, 10.74 and 4.28%e4
- Comparator
- normal light levels (CK)e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e3“In Nandou 12, the protein contents in plants shaded at R1R8, R2R8 and R5R8 were 9.20, 8.98 and 6.23% higher than in plants grown under normal light levels (CK), respectively”
e4“the crude fat content was 9.31, 10.74 and 4.28% lower”
Claim · model-written summary
Shading reduced light saturation point, light compensation point and maximum photosynthetic rate.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Shadinge5
- Outcome
- light saturation point (LSP), the light compensation point (LCP) and the maximum photosynthetic rate (Pnmax)e5
- Direction
- reducede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e5“Shading reduced the light saturation point (LSP), the light compensation point (LCP) and the maximum photosynthetic rate (Pnmax), and increased the apparent quantum yield (AQ)”
Claim · model-written summary
Shading increased the apparent quantum yield.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Shadinge5
- Outcome
- apparent quantum yield (AQ)e5
- Direction
- increasede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e5“Shading reduced the light saturation point (LSP), the light compensation point (LCP) and the maximum photosynthetic rate (Pnmax), and increased the apparent quantum yield (AQ)”
Claim · model-written summary
Shading increased antioxidant enzyme activity, with a larger increase under early shading.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Shadinge6
- Outcome
- antioxidant enzyme activitye6
- Direction
- increasede6
- Comparator
- latee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e6“Shading also increased the antioxidant enzyme activity in the plants, and this increase was greater with early shading than late”
Claim · model-written summary
Early shading had a greater effect on photosynthetic and related characteristics than later shading.
- Taxon
- soybeanGlycine maxt0
- Treatment
- early shadinge7
- Outcome
- photosynthetic and related characteristicse7
- Direction
- greater effecte7
- Comparator
- later shadinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e7“Compared with later shading, the early shading had a greater effect on the photosynthetic and related characteristics”
Claim · model-written summary
The longer the shading time, the greater the adverse effects on soybean and the less plants recovered.
- Taxon
- soybeanGlycine maxt0
- Treatment
- shading timee6
- Outcome
- adverse effectse6
- Direction
- greatere6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e6“The longer the shading time, the greater the adverse effects and the less able the plants' were to recover”
Claim · model-written summary
Chlorophyll variability at R2 was less than at R5 stage plants.
- Taxon
- soybeanGlycine maxt0
- Treatment
- R2 stagee7
- Outcome
- variability in the chlorophyll (a + b) content and the chlorophyll a/b ratioe7
- Direction
- lesse7
- Comparator
- R5 stage (VER5) plantse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean genotypes”
e7“The variability in the chlorophyll (a + b) content and the chlorophyll a/b ratio in R2 stage plants was less than in R5 stage (VER5) plants”
The same questions in other papers
shade · physiology: photosynthesis · Glycine max (soybean)Positive and negative results
8 papers in the same direction as this paper · 6 in the opposite direction
- positive
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See all 15 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.